Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 74 insertions, 0 deletions

diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
new file mode 100644
index 000000000..664701b75
--- /dev/null
+++ b/include/exec/ramblock.h
@@ -0,0 +1,74 @@
+/*
+ * Declarations for cpu physical memory functions
+ *
+ * Copyright 2011 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ *  Avi Kivity <avi@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * This header is for use by exec.c and memory.c ONLY.  Do not include it.
+ * The functions declared here will be removed soon.
+ */
+
+#ifndef QEMU_EXEC_RAMBLOCK_H
+#define QEMU_EXEC_RAMBLOCK_H
+
+#ifndef CONFIG_USER_ONLY
+#include "cpu-common.h"
+
+struct RAMBlock {
+    struct rcu_head rcu;
+    struct MemoryRegion *mr;
+    uint8_t *host;
+    uint8_t *colo_cache; /* For colo, VM's ram cache */
+    ram_addr_t offset;
+    ram_addr_t used_length;
+    ram_addr_t max_length;
+    void (*resized)(const char*, uint64_t length, void *host);
+    uint32_t flags;
+    /* Protected by iothread lock.  */
+    char idstr[256];
+    /* RCU-enabled, writes protected by the ramlist lock */
+    QLIST_ENTRY(RAMBlock) next;
+    QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers;
+    int fd;
+    size_t page_size;
+    /* dirty bitmap used during migration */
+    unsigned long *bmap;
+    /* bitmap of already received pages in postcopy */
+    unsigned long *receivedmap;
+
+    /*
+     * bitmap to track already cleared dirty bitmap.  When the bit is
+     * set, it means the corresponding memory chunk needs a log-clear.
+     * Set this up to non-NULL to enable the capability to postpone
+     * and split clearing of dirty bitmap on the remote node (e.g.,
+     * KVM).  The bitmap will be set only when doing global sync.
+     *
+     * NOTE: this bitmap is different comparing to the other bitmaps
+     * in that one bit can represent multiple guest pages (which is
+     * decided by the `clear_bmap_shift' variable below).  On
+     * destination side, this should always be NULL, and the variable
+     * `clear_bmap_shift' is meaningless.
+     */
+    unsigned long *clear_bmap;
+    uint8_t clear_bmap_shift;
+
+    /*
+     * RAM block length that corresponds to the used_length on the migration
+     * source (after RAM block sizes were synchronized). Especially, after
+     * starting to run the guest, used_length and postcopy_length can differ.
+     * Used to register/unregister uffd handlers and as the size of the received
+     * bitmap. Receiving any page beyond this length will bail out, as it
+     * could not have been valid on the source.
+     */
+    ram_addr_t postcopy_length;
+};
+#endif
+#endif